Fuel-oil burner



Oct.v23, 1928.

l. s. cHADwlcK E1' Al.

FUEL on. BURNER Fned July 18. 1924 el-sneets-sneet 1 ier /e vel FUEL OIL BURNER Filed July 1a, 1924 e sheets-sheet 5 I y 1,688,448 L.. s. CHADWICK Er AL FUEL OIL BUBNER Filed 'July 1a, 19.154l `6 snmp-sum 4 mn, M WDM f4/.g

Oct. 23, 1928.

L. s. CHADWCK ET AL FUEL. OIL BURNER Filed July 18, 1924 NQ WM RQ al.. ..1 |11 \N\ MS HH..%.................H..H

Oct. 23, 1928. 1,688,448v

L. s. cHADwlcK ET AL FUEL OIL BURNER Filed July 1s, v1924 6 sheets-sheet. 6

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Patented Oct. 23, 1928.

UNITED STATES PATENT OFFICE.

LEE S. CHADWICK, OFASHAKER- HEIGHTS VILLAGE, AND MARC RESEK AND JOHN ALGER DAHLSTROM, OF 4IEASL CLEVELAND, OHIO, ASSIGNORS TO PERFECTION STOVE COM- PANY, OF CLEVELAND, OHIO, .A CORPORATION OF OHIO.

FUEL-OIL Application filed July 18,

This invention relates to that class of fuel oil burning apparatus in which the oil is injected into the combustion space by steam which mixes with the atomized oil 5 to produce a highly combustible mixture,

and more particularly to that type of such apparatus wherein the steam is formed in a generator that is subjected to theiheat of the burner flame.

The fundamental objects of our invention are: v

First, to provide apparatus of the aforesaid class wherein the flame of the burner is governed through the controlling of the steam pressure by the amount of heat supplied to the generator; and,

j Second, to provide apparatus of the aforesaid class which, after being started, is automatic in maintaining a substantially constant flame, or one which has only a slight range of variation.

According to our present conception, the first of the foregoing objects may be accomplished in one of three ways: (a) By intercepting to a greater or less extent, ,as

by means of a damper or thelike, the passage of heat from a suitable source, as the flame of the burner, to the steam generator (b) by moving the generator bodily toward and from the source of heat or flame; and

(c) by changing the direction of the flame of the burner with respect to the generator.

In the attainment of the second of the foregoing objects, the steam pressure within the generator is used for` (a) shifting a damper between the source of heat or the flame and the generator; (b) .moving the generator toward and from the source of heat or the flame; (c) moving the burner so as to direct the flame either toward or against the generator, or at such an angle with respect thereto that it has no appreciable effect upon the generator.

Further and more general objects are to` 471 provide a highly efficient and thoroughly reliable burner of the aforesaid class which is of general adaptability, occupying little space and being suitable for use with hot air furnaces, steam boilers, forges, apanning f-U and enamelin ovens and the like; to provide fuel oil burn' ng apparatus of the class referred to which is comparatively simple of construction, is economlcal of manufacture and which may be readily installed in fur- BURNER.

1924. f serial No. 726,657.

naces, boilers, ovens and the like of prevaillng types; to provide a fuel oil burning apparatus of the principle above mentioned whlch is automatic in maintainin a substantially constant llame, or one o a given range of Variation, and which involves an adjustment whereby the flame or its range of variation, may be changed.

Our invention is not to be confused with that class of a paratus wherein an injector burner is supp ied with steam from a main boiler. In such cases the supply of steam to the burner is secondary to a major purpose, and usually the steam pressure required for such purpose is not suitable for the burner. Generally, it is toohigh, though occasionally too low. In the former instance, reducers, either automatic or manual, are necessary, and there is a considerable fluctuation in the steam pressure where the steam is used for a variety of purposes. Also, where only high pressure steam is available for operating the burner, the burner orifices for both steam and oil must necessarily be relatively small Jand as a consequence the orifices become easily clogged. Furthermore, in apparatus of this class, the starting of the burner is prolonged by the delay in building up a head of steam in the main boiler.

Our invention is more in the class of apparatus involving a steam generator whose sole purpose .it is to supply steam to the burner. In the past, in apparatus of this class, there has been no means for automatically regulating the steam pressure thereby to control the size of the flame. It is largely due to this discrepancy that such apparatus has failed to come into general use. They could not be left without attention for any material length of time and this disqualified them for such purposes as house-heating.

Like those of the foregoing class, our apparatus is compact and incorporates a steam. generator which supplies only the burner with steam; and in addition thereto it involves means for automatically main-1 taining a given steam pressure and consequently a given flame size by controlling the. amount of h eat delivered tothe generator; and moreover thereis an adjustment provided whereby the steam pressure and accordingly the flame sizevmay be varied. The

abutment 18.

422 of the plate 3.

apparatus may be set to maintain a steam pressure best suited to the requirements of the burner. This may be a comparatively low pressure, wherefore the steam and oil orioes of the burner may be relatively large, and this practically eliminates the possibility ofthe orifices becoming clogged.

The objects above related, with others which will appear as this description proceeds, are attained in the constructions illustrated in the accompanying drawings wherein Fig. 1 is a sectional side elevation, and Fig. 2 a front elevation of one form .of our invention; Fig. 3 is a sectional side elevation and Fig. 4` a sectional front elevation of another form of the invention; Fig. 5 is a sectional side elevation, Fig. 6 a plan" view, and Fig. 7 a front elevation of still another embodiment; while Fig. 8 is a sectional detail of the burner embodied in the last mentioned modification.

As previously mentioned, the invention is applicable to various types of furnaces or the like, and, in Fig. 1, walls which enclose the re box are represented generally at 1 and 2.

Applied to the front of the furnace is a plate 3, and a passageway 4 for air to the re box is provided by spacing the front of wall 2 a suitable distance, from the plate 3. Occupying the lower front portion of the fire box is a combustion chamber 5 that is built up of walls of refractory material. The top wall 7 of the combustion chamber is spaced from the front plate 3 to provide a passageway 8 which is adapted to be closed by a damper 9, shown as constructed of a channel 10 that carries a body 11 of lrefractory material, this assembly being carried by a yoke 12 that is shown as .constructed of side members 13 in the form of angle bars which are connected at their upper ends by a beam 14 including a knife edge bearing which rests in V notches of a bracket 15 thatis secured to the plate 3. Byreason of thisA mounting,` the damper may be swung with ease between aposition wherein it closes the passageway 8, and a second position wherein the passageway is open, as illustrated in Fig. 1. The plate 3 has an opening 16 through which the damper 9 swings. Adjacent its upper end, the yoke 12 carries an abutment 18. Opposed to the abutment 18, and adjustably mounted upon the front plate 3, is a support 19; and a spring 20 is compressed between the support and the The adjustment of the support 19 may be effected in any suitable manner as by providing the support with a threaded shank 21 which screws into a boss Afsteam generator 25 in the natureof a closed vessel' which has heat abstracting ribs 26 extending across its underneath surface, .is supported, as by` brackets 27 that,A are 'vention and may be replace secured by bolts 28 to the front plate 3, above the forward end of the top wall 7 and over vthe passageway 8, so that when the damper 9 is retracted the generator is exposed directly to the heat of the `flame of a burner 30 which extends through a hood 31 that. is applied to the front plate 3. The hood has a partition 32 which divides it into upper and lower Acompartments that communicate through a restricted passageway in the immediate vicinity of the burner. The `lower compartment opens into the previously mentioned passageway 4. Thus air is supplied from said passageway to the burner for the purpose of promoting combustion. Secondary air to support combustion in the chamber 5 is supplied through a grate 33. The hood may be provided with an opening .35 that is adapted to be closed by a door 36, preferably including a transparent pane of mica or the like so that the character ofthe burnerjiame may be observed at any time.

The burner is of the injector type and the oil jetv 38 of the burner is adapted to be supplied with fuel oil` from any suitable source through a pipe 39. The steam nozzle 40 of the burner communicates, through the conduit or pipe 41, with the top portion or steam space of the generator 25. A branch 42of the pipe or conduit 41 leads to the top of a water receptacle 44 that is supported by any suitable means forwardly of the front plate 3 and to one side of the yoke 12. A pipe or conduit 45 leads from the lpwer portion or Water space of the generator` to the water space of the receptacle 44, and a branch 46 of' this pipe extends upwardly and has connection with, a bellows 47 that is equipped with a stud 48 that bears against the abutment 18 of the yoke 12, The bellows 47is protected by a casing 50 and is supported through a bracket 51 .from the plate 3. Tater is conducted from anysuitable source, as the city supply, through a pipe 55 to the receptacle 44. The ingress of water to the receptacle is controlled b a suitable valve 56 that is actuated by a oat 57. This par ticular valve constitutes no art of our inby any other float mechanism or the like which is adaptable to the purpose. By this means a constant water level is vmaintained within the receptacle 44 and, by reason of the communication through the pipes 42 and 45 between the receptacle 44 and the generator 25, the same water level prevails at al1 times in the two vessels. It is also clear from what has already been described, that the steam pressure wlthin the generator 25 is communicated through the pipe 45 and branch 46 to the bellows 47.

To start the apparatus in operation it is necessary to heat the generator 25 by suitable means, as by a torch, pilot light or oill pan, thereby to create steam within the generator which is delivered through the pipe 41, to the steam nozzle of the burner 30. As the steam plays across the oil jet 38 it will suck out and atomize oil supplied through the pipe 39 and the resultant mix'- ture will burn within the combustion chamber 5. IVhen the damper 9 is in retracted position, as when starting the operation, the heat from the flame has access through the passageway 8 to the generator. Thus the steam pressure continues to b sild up within the generator with the result that the fire in-r creases and the heat becomes more intense" due to the fact that a great amount of oil is expelled from the jet 38 on account of the higher pressure and greater volume of steam. The pressure within the generator communicated through the pipes and 46 to the bellows 47 expands the bellows and forces the yoke 12 inwardly against the tension of the spring 20 thereby to swing the damper 9 to close or obstruct more or less the passageway 8. lVith the generator thus deprived of the intense heat of the flame, the pressure within the generator falls and as a consequence thereof the fire decreases. Also, the pressure within the bellows 47 subsides and vthe spring 20 is permitted to swing vthe yoke 12 in a direction to retract the damper 9 whereupon the generator is again exposed'to the direct, heat of the flame with the result that the steam pressure will rise and the foregoing operation will be repeated.

By adjusting the support 19 the tension of the spring` 20 will be varied and the temperature of the ireithus regulated. This is a very obvious resu t inasmuch as the steam pressure required to operate the bellows is dependent upon the tensio'n of the spring 20.

In all forms of the invention the size and consequently the heat of the flame is dependent upon the steam pressure within the generator and this is controlledl by the amount of heat delivered' to the generator. In the foregoing embodiment of the invention this is accomplished by interposing the damper 9 between the generatorl and the burner flame. f

In the form of the invention which we 4shall next describe, the same result is obtained by moving the generator-bodily toward and from the flame. This form of the invention is illustrated in Figs. 3 and 4 and the same is shown as comprising a hollow Ncasing that is fianged at its forward end and connected to a front plate 61, the forward end of the casing being o en and registering with an opening 62 1n the front plate that is covered by a suitable closurel 63. -The casing involves a partition 64 which divides the interior of the casing'into compartment-s 60a and 60". A combustion cliambe'ri, which may be constructed of suitable refractory material, is set downwardly in an opening in the top of the casing 60. The front wall of the combustion chamber has an opening 66 opposite a burner 67 which is carried by the partition 64. This burner is of the same general character as the one described in Connection with tbe previous embodiment of the invention and it includes a steam nozzle 70, and an oil jet 68 which receives fuel oil from a suitable source through a pipe 69.

Shown as supported upon brackets 72 which extend rearwardly from the front plate 61 is a water receptacle 73 which receives its supply through a pipe 74. The entra-nce of water to the receptacle 73 is controlled by a valve 75 which is adapted to be closed by mechanism involving a float 76 when the water within the re"eptacle has attained a given level. A steam generator 78 is supported by arms 79 above the combustion chamber 65, the top wall of the combustion chamber having an opening 80 directly above which the generator is normally supported. The arms 79 extend downwardly along the opposite sides of the casing` 60 and have knife-edge bearings 82 which rest in V-notches that are formed in brackets 83 that extend downwardly and outwardly from the casing 60.v At their lower ends, the arms 79 have extensions 85 which carry a cross beam 86. Threaded vertically through the middle of the cross beam is a screw 87 to the upper end of which is applied a cup 884that receives a stud 89 ydepending from a bellows 90. This bellows is housed within a cylindrical cavity 91 formed in the bottom wall of the casing 60 and the bellows communicates through ya pipe 92 with the receptacle 73. The lower portions of the receptacle 73 and the generator 78 are connected through a flexible conduit 94, while the tops of the vessels are connected through a similar ronduit 95. A pipe 96 leads from a part of the latter conduit adjacent the receptacle 73 to the steam nozzle 70 of the burner 67. y

To the lower end of the previously mentioned screw 87 is secured a beveled inion 98 which meshes with a similar pinion 99 on a shaft 100, said shaft being journaled in opposed branches of a U-shaped bracket 101 that is carried by the screw 87. The shaft 1'00 extends through a slot 102 in the front plate 61 and to its forward end is secured a hand wheel 103. v l

In the use of this form of the invention the operation is started as in the case above described, and when steam pressure is created within the generator 78 it is communicatedthrough the pipes and 96to the nozzle 70 of the burner. The steaml issuing from the nozzle 70 suks oil from the jet 68 and atomizes it and the mixture burns within the combustion chamber 65, the prodlas -the generator 78 thus increasing the steam pressure within the generator. The

creased pressure prevailing in the generator' 78 out of the direct path of the flame and away from the zone ofintense heat. As a consequence, vthe steam pressure will fall within the system and the flange will decrease in volume. Accordingly, the temperature of the parts will fall and the steam pressure subsiding, will allow the bellows 90 to, contract or shorten with the result that the generator will bereturned to its former position.

To regulate the temperature of the lire, the screw 87- may be adjusted by turning the hand wheel y103 to change the relation between the beam 86 and the bellows 90. This will cause the generator 78 to be shifted with respect to the' cbmbustion chamber and consequently will alter the conditions which are responsible for the character of the flame.

In the next form of the inventionthat illustrated in Figs. 5 to S-the steam pressure is controlled by moving the burner with respect to a fixed steam generator thereby to vary the intensity of the heat that is delivered to the generator. The present embodiment comprises a base 105 on which is mounted an open-top, cup-like steam generator 106 which is closed by a flexible wall or diaphragm 107, shown as clamped to the flanged upper end of the generator by means of a ring 108 that is secured to the ange by bolts 109. The generator lis disposed within a combustion chamber 110 enclosed by walls 111 of suitable refractory Inaterial. Mounted upon one end ofthe base 105 is a water receptacle 115 which receives its supply through la pipe 116 and wherein'a constant water level is maintained by a float 117 that controls the inlet valve 1-19. The lower portions of the receptacle 115 and the generator 106 communicate through a pipe 120, while communication is established between their upper portions through a pipe 121.

Supported a suitable distance above the end of the base opposite the receptacle. 115, is a burner 125 which is shown in detail'in ,Fig. 8. This burner, like those above de- I scribed, is of the injector type but is of a somewhat different form than 'the former ones. It comprises a shell 126 to the ends of which are applied heads 127 and 128. The former head has an orifice 130 in operative relation to which is disposed the end of an oil jet 131. The oil jet is supported centrally within the shell 126 by the head 128 and is supplied with fuel oil through a flexible conduit 133. Steam, is conveyed ,from the generator 106 through a pipe 135 and a flexible conduit 136 to the shell 126 of the burner.-

The burner is supported for oscillation upon ahorizontal axis, the support being effected by means of screws138 which are threaded through the upper ends of brackets 139 that rise from the `base 105.

Pivoted at 145 to a standard 146 which rises from one side yof "the generator 106 is a lever 147 which has a head, 148 at its'forward end that bears upon the diaphragm 107. The rear end of the lever 147 is connected, through a'link 149 with the corre` sponding end of a lever 150 that is pivoted at 151 to a bracket 152 that depends from.

the base 105. A link y154 has Vits upper and lower ends pivotally connected, respectively, to the rear end of theA burner 125 and to the forward end of the lever 150. The lever 150 plays through a guide 156 which is carried by the base 105 and the lower end of said guide constitutes a stop for limiting the depression of the adjacent end of the lever. The parts are so proportioned that when the forward end of the lever 150 is completely depressed 4the burner is in a position to direct its products' against the generator 106.

ber L110, supplying heat to the generator 106,

and as the steam pressure in the generator increases the diaphragm 107"is distended to rock the .lever 147 and, through the link 149, the lever 150 in a direction to elevate the link 154 and rock the burner '125' upon its axis of oscillation to a position in which the flame is directed above the generator, thus permitting the temperature of the generator to fall and consequently the pressure within the system to subside whereupon the flame decreases and as a consequence thereof the parts resume their former positions.

Having thus described our invention, what we claim is l 1. In combination, a. steam operated oil burner of the 'injector type wherein the oil flow is solely responsive to the flowof steam, a steam generator exposed to a source of heat, a conduit of constant capacityleading from 'the steam nerator1 to the burner whereby the stea supply to the burner varies according to the Vsteam pressure in the generator, means for conducting fuel oil to the burner, means for varying the amount of heat delivered to the generator thereby to control the steam pressure therein and consequently the amount of steam delivered to the burner, means constantly subjected to and operated by the variable steam pressure in the generator for actuating the last mentioned means, and further means of variable resistance opposing the action of said last mentioned means.v

2. In combination, a steam operated oil burner of the injector type wherein the oil flow is solely responsive to the liow of steam, a steam enerator exposed to the products ot' combustion therefrom, a conduit of constant capacit leading :from the steam generator to the urner whereby the steam supply to the burner varies according to the steam pressure in the generator, means for supplying the burner with fuel oil, a damper shiftable to and from a position wherein it shields the generator from the products, 'a steam pressure device constantly subjected to and operated by the varying steam pressure in the generator for moving the damper to said position, and means opposing the action of said device and serving to retract the damper from said position.

3. In combination, a steam operated oil burner of the injector type wherein the oil flow is solely responsive to the flow of steam, a steam generator exposed to the products of combustion therefrom, ay conduit of constant capacity leading from the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, means for sup lying the burner with fuel oil, a damper s iftable to and from a position wherein it shields the generator from the products, a steam pressure device for moving the damper to said position, a conduit through which uninterrupted communication is established between the steam generator and said device whereby said device is constantly subjected to the varying steam pressure in the generator, a spring opposing the action of said device and serving to retract the damper from said position, and means for adjusting the'tension of said spring.

4. In apparatus of the character set forth, the combination of a structure enclosing a combustion chamber, a steam operated oil burner of the injector type wherein the oil flow is solely responsive to the flow of steam, said burner being supported in a position to project' its products of combustion into said chamber, a steam generator supported outside the combustion chamber, there being a passageway through which a part of the products may pass from said chamber to the generator, a damper 'for controlling said passageway, a steam pressure device for operating the damper,`a conduit through which uninterrupted communication is established beto the burner.

5. -In apparatus of the character set forth, the combination of a structure enclosing a combustion chamber, a steam operated oil burner ot' the injector type wherein the oil flow is solely responsive to the llow of steam, said burner being supported in a position to project its products ot' combustion into said chamber, a steam generator supported outside the combustion chamber, there being a passageway through which a part of the products may pass from the chamber to said generator, a damper for controlling said passageway, a member carrying the damper and supported for swinging movement, means tending to swing said member in a direction to open the damper, a stream pressure device for moving said member in the direction to close the dampeiy'a conduit through which uninterrupted communication is established between the steam generator and said device whereby said device is constantly subjected to the varying steam pressure in the generator, a conduit of unchanging capacity leading from the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, and means for supplying fuel oil to the burner.

In apparatus of the character set forth,

the combination of a structure enclosing a side the combustion chamber, there being a passageway for a part of the products from said chamber to the generator, a member supported by the structure'v for swinging movement, a. damper carried by' said member for controlling said passageway, a spring tending to swing said member in a direction to retract the damper from the passageway, a pressure fluid device through which the member is swung in a direction to project the damper across the passageway, conduit through which uninterrupted communication is establishedbetween the steam generator and said device whereby said device is constantly subjected to the, varying steam pressure in the generator, a conduit of unchanging capacity leading from the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, means for supplying fuel oil to the burner, and means for adjustingthe tension of the aforesaid sprin I 7. n combination, a steam operated oil burner of the injector type wherein the oil flow is solely responsive to the flow of steam, a steam generator exposed to a source of heat,

, a conduit of constant capacity leading yfrom opposing means.

the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, means for conducting fuel oil to the burner, means for varying the amount of heat de'- livered to the generator thereby to control the steam pressuredelivered to the burner, means constantly subjected to and operated by the variable steam pressure in the generator for actuating the last mentioned means, further means of variable resistance opposing the action of said last mentioned means, and an adjustment for varying the resistance of the 8. In combination, a. steam operated oil burner ofthe injector type, wherein the oil flow is solely responsive to the flow of steam,

s a steam generator exposed to a source of heat, a conduit of constant capacity leading f from the steam generator to the burner whereby' the steam supply to the burner varies according to the steam ressure in the generator, means for conducting fuel oil to the burner, means for varying the amount of heat delivered to the generator thereby to control the steam pressure delivered to the burner, means constantly` subjected to and operated by the variable steam pressure in the generator for actuating the last mentioned means, and vfurther means opposingv with .gradually increasing resistance the action of saidlast mentioned means.

9. In apparatus of the character set forth, i

the combination of a structure including a combustion chamber, a steam operated oil burner of the injector type wherein the oil How is solely responsive to the How of steam,

said burner being sup orted in a position to project its products o combustion into said chamber, a steam generator supported outside the combustion chamber, there being a passageway through which a part of the products may pass from the chamber to said generator, a damper for controlling said passageway, a member carrying the damper and supported for swing movement, a spring tending to swing said member in a direction to open the damper, a steam pressure device for moving said member in opposition to said spring in a direction to close the damper, a conduit through which uninterrupted communication is established between the steam generator and said device whereby said device is constantly subjected to the varying steam pressure in the generator', a conduit of unchanging ca acity leading from the steam generator to t e burner whereby the steam in the top wall of said `chamberbelow the,

generator, a bearing supported by the front of the structure above the combustion chamber, a frame swung from said bearing, a

damper carried by the lower end of said v frame for controlling the passage of products through the aforesaid opening, a steam pressure device for swinging said frame in a direction to project the damper across said opening, a conduit through which uninterrupted communication is established between the steam generator and said device whereby said device is constantly subjected to the varying steam pressure in the generator, a conduit of unchanging capacity leading from the steam generator to` the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, and means for supplying fuel oil tothe burner.

11. In apparatus of `the character set forth, the combination of a structure including a combustion chamber, a burner of the insaid bearin a damper carried by the lower end of sai frame for controlling the passage of products through the aforesaid opening, the frame incorporating an abutment, a bellows supported 1n opposed relation to said abutment and incorporatin a thrust member engaging'one side of sai abutment, a spring seat in o posed relation to the opposite side of the a utment, a spring interposed between said seat and the abutment, a conduit through which communication is established between the steam generator and the bellows, the bellows when expanded serving to swing the frame in opposition to said spring in a direction to project the damper across the aforesaid opening, a conduit leading from the steam generator to the burner, and means for supplying fuel oil to the burner.

12. In apparatus of the character set forth, the combination of a structure including a combustion chamber, a burner of the injector type supported in a position to project its products of combustion through the front of and into said chamber, a steam generator situated immediately above the front portion of the combustion chamber, there being an opening in the top wall of said chamber below the generator,`a bearing supported b the front ofthe structure above the combustion chamber, a frame swung from said bearing, a damper carried by the lower end of said frame for controlling the passage of products through the aforesaid opening, said frame incorporating an abutment, a spring seat adjustably supported by the structure in opposed relation to one side of the abutment, a s ring interposedl between said seat an the abutment, a bellows supported in opposed relation to the oppositeside of the abutment having a part bearing against the abutment, a conduit through which communication is established between the steam generator and the bellows, a conduit leading from the steam generator to the burner, and means for supplying fuel oil to the burner.

13. In combination, a steam operated oil` burner of -the injector type wherein the oil How is solely responsive to the flow of steam7 a steam generator exposed to a source of heat, a conduit of constant capacity leading from the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator,

means Afor conducting fuel oil to the burner, means for varying the amount of heat delivered to the generator thereby to control the steam pressure therein and consequently the amount of steam delivered to the burner, and means constantly subjected to and operated by the variable steampressure in the lgenerator for actuating the lasttmentioned means. y t, 14. In combination, al steam operated 'oil burner of the injector type wherein the oil flow is solely responsive to the iow of steam, a steam generator exposed tothe products of combustion therefrom, a conduit of constant capacity leading from the steam generator to the burner whereby the steam supply to the burner varies according to the steam pressure in the generator, means for supplying the burner with fuel oil, a damper shiftable to and from a position wherein it shields the generator from the products, a steam pressure device for moving the damper to said position, a conduit establishing uninterrupted communication between the steam generator and said device whereby said device is constantly subjected to the varying steam pressure in the generator, means tending to retract the damper from said position, and an adjustment whereby the steam pressure required to move the damper to said position may be varied.

In testimony whereof, we hereunto aiix our signatures.

LEE S. lCHADWICK.

MARC RESEK. J. ALGER DAHLSTROM. 

